As we age, our lenses undergo physiological changes that make it more difficult to focus on near objects. That is why nearly everyone requires reading glasses, even as early as age 35-40. The ability of the eye to change focal power, also known as accommodative amplitude, decreases significantly with age. The accommodative amplitude is 20 diopters in children and young adults, but it decreases to 10 diopters by age 25 and to ≦1 diopter by age 60. The age-related inability to focus on near objects is called presbyopia. All of us will develop presbyopia and will use corrective lenses unless a new treatment is found.
Both presbyopia and cataract are age-related and may share common etiologies such as lens growth, oxidative stress, and/or disulfide bond formation.
There is a need for compositions and methods for combating presbyopia and/or cataract, particularly compositions and methods that minimize toxicity to surrounding healthy tissues.